190 likes | 490 Views
Calculation of Range of Dilutions for Acceptable BOD Results. Prepared By Michigan Department of Environmental Quality Operator Training and Certification Unit. BOD PROCEDURE. DILUTE SAMPLE. Minimum Residual, 1.0 mg/L Minimum Depletion, 2.0 mg/L At Least Two Dilutions. Depletion. X.
E N D
Calculation of Range of Dilutions for Acceptable BOD Results Prepared By Michigan Department of Environmental Quality Operator Training and Certification Unit
BOD PROCEDURE DILUTE SAMPLE Minimum Residual, 1.0 mg/L Minimum Depletion, 2.0 mg/L At Least Two Dilutions
Depletion X 300 mL BOD Sample = Sample Volume Minimum Depletion X 300 mL Minimum BOD = Sample Volume 2.0 X 300 Minimum BOD = Sample Volume 600 Minimum BOD = Sample Volume Calculation of Range of Acceptable BOD Results Lowest (Minimum) Acceptable Results – Lowest Acceptable Depletion
600 600 Minimum BOD = Minimum BOD = Sample Volume 20 600 Minimum BOD That May Be Reported = Sample Volume Example What is the Lowest Acceptable BOD results if 20 mL of sample is used? Minimum Acceptable BOD = 30 mg/L
600 600 Minimum BOD = Minimum BOD = Sample Volume 150 Example 2 What is the Lowest Acceptable BOD results if 150 mL of sample is used? Minimum Acceptable BOD = 4 mg/L
D.O. In – 1.0 X 300 mL Maximum BOD = Sample Volume 7.0 X 300 Maximum BOD = Sample Volume 2100 Maximum BOD = Sample Volume Calculation of Range of Acceptable BOD Results Highest (Maximum) Acceptable Results – Highest Acceptable Depletion Lowest Acceptable Residual ASSUMING Initial D.O. of 8.0 mg/L Depletion = 8.0 - 1.0 = 7.0
2100 2100 Maximum BOD = Maximum BOD = Sample Volume 20 2100 Maximum BOD That May Be Reported = Sample Volume Example What is the highest Acceptable BOD results if 20 mL of sample is used? Maximum Acceptable BOD = 105 mg/L
2100 2100 Maximum BOD = Maximum BOD = Sample Volume 150 2100 Maximum BOD That May Be Reported = Sample Volume Example 2 What is the highest Acceptable BOD results if 150 mL of sample is used? Maximum Acceptable BOD = 14 mg/L
Lowest (Minimum) Acceptable Results – Lowest Acceptable Depletion Highest (Maximum) Acceptable Results – Highest Acceptable Depletion Lowest Acceptable Residual (Assuming D.O. In =8.0 mg/L 2100 600 Maximum BOD = Minimum BOD = Sample Volume Sample Volume Calculation of Range of Acceptable BOD Results Summary
2100 600 Maximum BOD = Minimum BOD = Sample Volume Sample Volume Calculation of Range of Acceptable BOD Results Wait A Minute 600X 3.5 = 2100 So (assuming D.O. In is 8.0) Minimum BOD x 3.5 = Maximum BOD
Lowest (Minimum) Acceptable Results – Lowest Acceptable Depletion Highest (Maximum) Acceptable Results – Highest Acceptable Depletion Lowest Acceptable Residual (Assuming D.O. In =8.0 mg/L Maximum BOD = 3.5 X Minimum BOD 600 Minimum BOD = Sample Volume Calculation of Range of Acceptable BOD Results Summary (again)
600 Minimum BOD = 30 Example What is the Lowest Acceptable BOD results if 30 mL of sample is used? = 20 mg/L What is the Highest Acceptable BOD results if 30 mL of sample is used? 20 mg/L X 3.5 = 70 mg/L Total Range when using a 30 mL sample: 20 to 70 mg/L
Total Range when using a 100 mL sample = 6 to 21 mg/L Total Range when using a 150 mL sample = 4 to 14 mg/L Total Range when using 100 mL and 150 mL (two Bottles) = 4 to 21 mg/L OVERLAP From 6 to 14 mg/L Total Range when using a 50 mL sample = 12 to 42 mg/L Total Range when using 50 mL and 150 mL (two Bottles) = 4 to 42 mg/L OVERLAP From 12 to 14 mg/L
Total Range when using a 25 mL sample = 24 to 84 mg/L Total Range when using a 125 mL sample = 4.8 to 16.8 mg/L Total Range when using 25 mL and 125 mL (two Bottles) = 4.8 to 84 mg/L ? NO: Does Not Include 16.8 to 24 mg/L Range To Wide (No Overlap)
Calculate Range of Acceptable BOD Results Use Two Volumes that Expand the Range But Give a “Comfortable” Overlap
Calculate Range of Acceptable BOD Results Use Two Volumes that Expand the Range But Give a “Comfortable” Overlap
Calculate Range of Acceptable BOD Results Use Two Volumes that Expand the Range But Give a “Comfortable” Overlap
Calculation of Range of Dilutions for Acceptable BOD Results Prepared By Michigan Department of Environmental Quality Operator Training and Certification Unit